Embodiments described herein relate generally to apparatus and methods for optimizing flow of a bodily fluid, and more particularly, devices, systems, and methods to facilitate blood flow from the heart to a blood pump.
The use of devices to assist the function of an ailing heart is increasing. In some instances, a ventricular assist device (VAD) can be used to partially or completely replace the function of the heart. For example, in some instances, a left ventricular assist device (LVAD) can be used to assist a heart of a patient by placing an inlet flow cannula in fluid communication with the left ventricle of the heart and an outlet flow cannula in fluid communication with a portion of the aorta. The LVAD can include a pumping mechanism that can pump, transfer, draw, push, or otherwise produce a flow of blood between the inlet flow cannula and the outlet flow cannula, thereby assisting heart. The chamber of the left ventricle can be relatively large to act as a suitable source for blood pump inflow and the wall of the left ventricle is relatively thick to support the inlet flow cannula. Known methods for coupling an inlet flow cannula to the left ventricle, however, often require major surgery, which can damage the heart or surrounding tissue and/or can result in death of the patient. Such known procedures can also be relatively expensive due to long surgical times and/or the complexity and risk of the surgery. Furthermore, in some instances, the drawing of blood through the inlet flow cannula can produce a negative pressure within the left ventricle that can cause a wall of the left ventricle to collapse, thereby obstructing the inlet flow cannula and/or other veins.
In some instances, an inlet flow cannula can be placed in or at a desired location within, for example, the left atrium which can reduce the complexity, severity, risk, and/or cost of placing an assist device. In some such instances, the inlet flow cannula is advanced through the superior vena cava (SVC) and is coupled to the septum between the right atrium and the left atrium. In other instances, the inlet flow cannula can be coupled to the dome of the left atrium. Placing the inlet flow cannula in fluid communication with the left atrium, however, can be complicated by the anatomy of the heart. For example, the walls of the left atrium are very thin (e.g., between 1 and 2 mm in thickness) and the interior of the left atrium can be at a relatively low pressure, due to the function of the heart, which can increase the likelihood of tissue collapsing into the left atrium. Such a collapse of tissue can obstruct the inlet flow cannula and/or can result in undesirable kinking of veins in fluid communication with the left atrium. Thus, the inflow rates to the blood pump using such methods can be limited, which can result in poor efficiency of the pump and can result in clot formation.
Thus, a need exists for devices, systems, and methods to improve flow of blood from the heart to a blood pump.